Device for deposition of a fluid material, manipulator therefor, and procedure for using said device

ABSTRACT

A device including a cavity defined by walls (17) having a feed opening (18) and an outlet (19) for the fluid material (m). The outlet (19) is connected to a nozzle (20). The device is suitable for measuring, controlling and depositing the material (m).

BACKGROUND OF THE INVENTION

The invention relates to the deposition of a hardenable fluid or viscousmaterial. It concerns, first, a device for measuring and regulating theflow rate of a fluid or viscous material. The device comprises anopening for feeding fluid into a cavity delimited by walls. The cavitycontains means for controlling the transport of the material to anoutlet orifice in the cavity.

The technique used to regulate the flow rate of a fluid is known (see,for example, French Patents Nos. FR 1 074 689 and FR 1 323 988). Theseknown flow rate-measurement and regulating devices do not permit thedeposition of a hardenable fluid material on an object. In addition,these known devices are bulky and heavy, thereby adversely affecting theuse or shipment thereof by a human operator or robotic manipulator, and,accordingly, the deposition of the material along a three-dimensionalcurve incorporating a complex shape.

Furthermore, it is not possible to connect these known devices, forexample using flexible tubing, to a mobile deposition nozzle, becausethe hardenable fluid materials are often expandable and compressive whensubjected to pressure.

In this situation, the tube expands due to pressure variations, with theresult that the flow rate of the pump no longer corresponds to the flowrate of the nozzle.

The invention is intended to solve these difficulties. To this end, thedevice according to The invention has an outlet orifice which emptiesinto a deposition nozzle made integral with the walls of a cavity.

To regulate flow rate continuously, the fluid-propulsion mechanism is agear assembly in which the axis of each pinion is substantiallyperpendicular to the axis of the outlet orifice of the cavity.

The fluid-propulsion mechanism is actuated by a motor, in particular anelectric motor.

Flow rate is proportional to the rotation of the gears, and thus, to therotation of the electric motor, the controlled rotation of which allowsmeasurement of the flow rate.

To obtain a pressure differential approaching zero, i.e., a high degreeof adjustment precision without internal material leakage, the deviceincorporates two pressure bleeds, one of which is up-line, and the otherdown-line, from the cavity.

Reduction of this internal leakage increases volumetric efficiency andprevents overheating that could adversely affect the material.

In order to keep viscosity within a narrow range and to handle thematerial, the cavity walls generate heat, for example using cartridgeshoused in holes, and a heating plate is added to the device, or else anozzle-, motor-, and/or manipulator-positioning heating element isattached to the device according to the invention.

The nozzle comprises an extrusion orifice incorporating, at the endthereof, an adjustable opening/closing valve, thereby making it possibleto obtain a "zero" cavity, that is, a cavity without material in contactwith the outside, which could otherwise harden and clog the nozzle.

The invention also concerns a manipulator, in particular a robot of thetype incorporating a mobile body on which is mounted a jointed armhaving, at its end, a revolving wrist attached to a fluid-depositiongun, the gun comprising an opening for fluid-feed to a cavity delimitedby at least one wall, the cavity housing gears for fluid propulsion toan outlet orifice, in which the gun corresponds to the aforementioneddevice.

The invention further relates to a procedure for deposition of ahardenable fluid or viscous material, deposition occurring by means ofthe flow of the material into a nozzle, wherein the material is heated,then the flow rate of the material is measured and adjusted, therebyallowing variation of the outlet flow rate of the material during asingle deposition operation. Accordingly, if the manipulator slows, itis possible to adjust the flow rate in order to preserve the same linearweight of the deposited product.

BRIEF DESCRIPTION OF THE FIGURES

One embodiment of the invention will now be described with reference tothe attached drawings, in which:

FIG. 1 is a schematic, perspective view of a material-depositionapparatus comprising a device and a manipulator according to theinvention,

FIG. 2 is a view in cross-section of the device used in this apparatus,and

FIG. 3 is a raised, partially torn-away view of the cavity of thedevice.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The apparatus in FIG. 1 comprises a robot 1 operating a deposition gun2.

The gun 2 is fed with a foaming material m through a flexible tube 3 bymeans of a piston pump 4 positioned on a drum 5 serving as a tank forthe material.

The gun 2 deposits the material m on the upper periphery 6 of acylindrical object 7 attached to a table 8.

The robot 1 moves on slide-rails 8.

The robot 1 is fitted with a wrist 9 for immobilization of the gun 2,the said wrist 9 forming the end of an arm 10 mounted on the body 11 ofthe robot 1. The body 11 is, in turn, mounted on blanks 12, 13 attachedto a support 14 which revolves in relation to a base 15.

The robot comprises six joints having axes a, b, c, d, e, and fpositioned, respectively, at the junction of the base 15 with thesupport 14, of the blanks 12, 13 with the body 11, of the body 11 withthe arm 10, on the arm, at the junction of the arm 10 and the wrist 9,and on the wrist 9. The combination of these six joints having axes a,b, c, d, e, and f allows the gun 2 to occupy any position in space.

The gun 2 has a housing 16 delimited by six plane walls 17. One wallincorporates a feed opening 18; the wall opposite incorporates an outletorifice 19 emptying into a nozzle 20. An electric motor 21 controlled byan electronic variable-speed drive unit E is attached to a third wall17.

The nozzle 20 and the motor 21 are positioned on the housing 16 by meansof a heating support element 22 composed of three plates 22a, 22b, and22c arranged perpendicularly in space. The plates are heated using twothermoregulated cartridges 23, 24. The tube 3 for feeding the foamingmaterial m is fastened to the feed opening 18 by a collar 25. A duct 26connects the outlet orifice 19 to the nozzle 20 through the heatingplate 22a. Two pressure bleeds 27, 28 are mounted, respectively, on thecollar 25 and the outlet of the duct 26 in the nozzle 20. The nozzle 20comprises a hollow, conical extrusion orifice 29 that can be sealed by arod 30 forming a valve and made integral with a pneumatic operating jack31. A screw 32 located at the end of the jack 31 opposite the valvecontrols the opening of the valve.

The housing 16 contains a gear assembly or mechanism composed of twopinions 33 and 34, as shown in FIG. 3. The pinion 33 is driven by ashaft 35 transmitting the movement of the motor 21. The second pinion 34is mounted on a shaft 36. The parallel shafts 35 and 36 are mountedperpendicularly to the outlet orifice 19.

The apparatus works in the following way. The foaming material m ispumped from the tank 5 by the pump 4, which feeds the mobile gun 2through the flexible tube 3.

The robot 1 positions and shifts the extrusion orifice 2 integral withthe gun 29. The flexibility of the tube 3 allows the gun to be fed atvariable distances from the tank 5.

The product is transported to the outlet orifice 19 by the rotation ofthe pinions 33, 34. The pinion 34 is driven by the pinion 33, whoserotation is controlled by the motor; in this way, the motor controls theflow rate. The robot gives the command to start the motor and open thenozzle when it has brought the gun 2 into the working position. At thismoment, the foaming material flows at a regulated flow rate, therebymaking it possible to produce the repeated deposition of a ribbon offoaming material. Deposition takes place by virtue of the fact that therobot 1 moves the nozzle 20 above the area to be covered. The cycle endswhen the nozzle is closed and, simultaneously, the robot stops themotor. The robot then brings the gun 2 back into its stand-by position.

The use of an electric motor 21 equipped with its variable-speed driveunit E allows variation of the flow rate of the foaming material mduring a deposition cycle.

The invention is not limited to the embodiment described. As a variant,the manipulator may be a motorized slide-rail.

I claim:
 1. A device for measuring and regulating the flow rate of aviscous fluid material (m), said device comprising:a) gun equipped witha cavity delimited by at least one wall (17), said cavity incorporatinga fluid-feed opening (18) and an outlet orifice (19) emptying into adeposition nozzle (20) integral with said at least one wall, and b) amechanism for transporting the material to the nozzle, c) wherein themechanism for transporting the material is capable of regulating theflow rate of the material and is a gear mechanism disposed in saidcavity.
 2. A device according to claim 1, wherein the gear mechanismcomprises pinions (33, 34) having axes substantially perpendicular to anaxis of the outlet orifice of the cavity.
 3. A device according to claim1, wherein the gear mechanism is driven by an electric motor (21).
 4. Adevice according to claim 1, further comprising two pressure bleeds (27,28) disposed upstream and downstream from the cavity.
 5. A deviceaccording to claim 1, wherein the at least one wall of the cavityproduces heat using cartridges (23, 24) housed in holes.
 6. A deviceaccording to claim 1, further comprising a heating plate (22a) disposedon the gun.
 7. A device according to claim 3, further comprising aheating element (22) attached to one of the nozzle and the motor.
 8. Adevice according to claim 1, wherein the nozzle comprises an extrusionorifice incorporating, at an end thereof (29), an adjustableclosing/opening valve (30).
 9. A robot manipulator, comprising,a) amobile body (11), b) a jointed arm (10) mounted on said body, andincorporating, at an end thereof, a revolving wrist (9), and c) a devicefor measuring and regulating the flow rate of a viscous fluid material,as defined in claim 1, attached to said wrist.